A fully premixed burner

Abstract

The present application relates to the technical field of gas turbine, in particular to a full premix burner, comprising: a main air inlet member, a main fuel cavity is arranged in the outer layer of the main air inlet member, and a front premix cavity is further arranged; the main fuel cavity is communicated with the front premix cavity through a main fuel hole; a main air hole is arranged on the main air inlet member and communicated with the front premix cavity; a nozzle outer cylinder is connected with the main air inlet member and provided with a rear premix cavity communicated with the front premix cavity; a nozzle inner cylinder is provided with a duty premix cavity; a duty air hole communicated with the duty premix cavity is arranged on the nozzle outer cylinder; the duty premix cavity is communicated with a duty fuel passage; the present application adopts premix combustion in the whole process through premixing of the main air and the main fuel and premixing of the duty air and the duty fuel; the main air and the main fuel and the duty air and the duty fuel can be uniformly mixed, and stable flame is formed in the combustion chamber; the temperature of the combustion flame surface is low, and the emission of NOx is greatly reduced. x Pollutants.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and more specifically to a fully premixed combustor. Background Technology

[0002] The combustion of gaseous fuels in gas turbines mainly occurs through two methods: diffusion combustion and premixed combustion. Diffusion combustion refers to the process where fuel and air are mixed and burned simultaneously within the combustion chamber without prior mixing. Because the flame equivalence ratio in diffusion combustion is approximately 1, the combustion temperature is high and the flame is stable; however, NO... x The emission concentration is relatively high. Premixed combustion refers to the method of pre-mixing fuel and air into a homogeneous mixture before ignition and combustion in the combustion chamber. Premixed combustion can reduce the combustion temperature by adjusting the equivalence ratio at the flame front, resulting in lower NO emission concentrations. x It has advantages in emissions, but its combustion stability is poor.

[0003] Currently, most heavy-duty gas turbines in service employ dry, low-NOx staged combustion technology. Most of the fuel entering the gas turbine is burned and releases heat through premixed combustion, while the remaining small portion is burned through diffusion combustion to ensure combustion stability. For example, in GE's DLN2.0+ burner and Mitsubishi's DLN Mk8-4 burner, the fuel participating in premixed combustion is mainly injected through fuel orifices on the swirl vanes and then mixed with the mainstream air. However, the mixing distance is relatively short, resulting in uneven fuel-air mixing. This uneven mixing leads to combustion instability, increased pollutant emissions, and low combustion efficiency, and in severe cases, can damage high-temperature components such as the combustion chamber and turbine. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of uneven mixing of fuel and air during premixed combustion of gas turbines, which leads to unstable combustion, increased pollutant emissions and low combustion efficiency.

[0005] To overcome the above-mentioned defects, the present invention provides a fully premixed burner, comprising:

[0006] The main intake component has a main fuel chamber on its inner and outer layers, and a pre-premixing chamber inside the main intake component; the main fuel chamber is adapted to communicate with the main fuel passage; the main fuel chamber is connected to the pre-premixing chamber through multiple main fuel holes; multiple main air holes are provided on the outer wall of the main intake component, and the main air holes are connected to the pre-premixing chamber; the main fuel passage is a channel with an annular cross-section.

[0007] The nozzle outer cylinder is connected to the main air intake component; a rear premixing chamber with an annular cross-section is provided inside the nozzle outer cylinder; the rear premixing chamber is connected to the front premixing chamber;

[0008] The nozzle inner cylinder is spaced inside the nozzle outer cylinder; a shift premixing chamber with an annular cross-section is provided inside the nozzle inner cylinder; the shift premixing chamber is adapted to communicate with the shift fuel passage, which is an annular cross-section passage fitted inside the main fuel passage; multiple shift air holes are provided on the outer wall of the nozzle outer cylinder, and the shift air holes are connected to the shift premixing chamber; both the rear premixing chamber and the shift premixing chamber are adapted to communicate with the combustion chamber.

[0009] Optionally, a plurality of main air holes are uniformly arranged at the outer end and outer periphery of the main air intake component, and each main fuel hole is arranged close to the main air hole.

[0010] Optionally, a double-layer hollow cup structure is provided inside the main air intake component; the double-layer hollow cup structure includes: an inner hollow cup formed by an inner first guide plate and an outer hollow cup formed by an outer second guide plate;

[0011] Both the first and second guide vanes are horn-shaped;

[0012] The first horn opening at the outer end of the first guide vane corresponds to the outer end of the main air intake component, and the space enclosed inside the first guide vane forms a central mixing zone; the central mixing zone is suitable for mixing fuel and air introduced from the outer end of the main air intake component.

[0013] The second horn opening at the outer end of the second guide plate is positioned inward relative to the first horn opening; the space enclosed by the interior of the second guide plate and the exterior of the first guide plate forms an intermediate mixing zone; the intermediate mixing zone is suitable for mixing fuel and air introduced from the front outer periphery of the main air intake and fuel and air mixed in the central mixing zone introduced through the gap provided in the first guide plate.

[0014] The space outside the second guide vane forms an outer mixing zone; the outer mixing zone is suitable for mixing fuel and air introduced from the rear outer periphery of the main air intake and fuel and air mixed in the intermediate mixing zone introduced through the gaps provided in the second guide vane.

[0015] Optionally, a main cyclone separator is provided in the front part of the post-premixing chamber.

[0016] Optionally, a cyclone separator is provided in the rear part of the premixing chamber.

[0017] Optionally, a purge air passage is provided inside the premixing chamber and the fuel passage; the purge air passage communicates with the combustion chamber through a purge air hole at the rear end.

[0018] Optionally, a hollow purge rod is provided inside the premixing chamber, with the rear end of the purge rod located near the rear of the premixing chamber.

[0019] Optionally, a purging cooling channel is provided near the rear end of the purging rod, and a cooling air hole is provided on the outer periphery of the purging air channel, the cooling air hole being connected to the purging cooling channel.

[0020] Optionally, the front end of the main air intake component is connected to a burner connecting flange, and both the main fuel passage and the standby fuel passage are located within the connecting flange.

[0021] Optionally, the duty fuel channel extends into a portion of the space of the duty premixing chamber; the duty fuel channel communicates with the duty premixing chamber through a duty fuel hole located near the outer periphery of the end; the duty air hole is located in front of the duty fuel hole.

[0022] The technical solution of the present invention has the following advantages over the prior art:

[0023] 1. The fully premixed burner provided by the present invention comprises: a main air intake component, having a main fuel chamber on its inner and outer layers, and a pre-premixing chamber inside the main air intake component; the main fuel chamber is adapted to communicate with a main fuel channel; the main fuel chamber communicates with the pre-premixing chamber through multiple main fuel holes; multiple main air holes are provided on the outer wall of the main air intake component, the main air holes communicating with the pre-premixing chamber; the main fuel channel is an annular cross-section channel; an outer nozzle cylinder connected to the main air intake component; a rear premixing chamber with an annular cross-section is provided inside the outer nozzle cylinder; the rear premixing chamber communicates with the pre-premixing chamber; and an inner nozzle cylinder spaced inside the outer nozzle cylinder; an annular cross-section is provided inside the inner nozzle cylinder. The premixing chamber is configured to communicate with a premixed fuel channel, which is an annular cross-section channel fitted inside the main fuel channel. Multiple premixed air holes are provided on the outer wall of the nozzle outer cylinder, and these holes communicate with the premixing chamber. Both the post-premixing chamber and the premixing chamber are configured to communicate with the combustion chamber. This application adopts the above technical solution, designing premixing of main air and main fuel, as well as premixing of premixed air and premixed fuel, with premixed combustion used throughout the entire process. This ensures that the main air and main fuel, as well as the premixed air and premixed fuel, are uniformly mixed before combustion, forming a stable premixed combustion flame in the combustion chamber. Compared to diffusion combustion, due to the lower flame surface temperature, it has NO... x The advantage of low emissions; that is, significantly reducing NO emissions. x Pollutant emissions.

[0024] 2. In this invention, multiple main air holes are uniformly arranged at the outer end and periphery of the main air intake component, and each main fuel hole is located close to the main air hole. Using the above technical solution, when the main air enters the premixing chamber through the main air holes, a localized backflow entrainment zone is formed on the back side of the main air holes. By positioning the main fuel holes close to the main air holes, the main fuel, once ejected, is entrained and mixed with the main air, which helps to enhance the mixing of air and fuel and improve the uniformity of fuel mixing. Since premixed combustion is very sensitive to fluctuations in the air-fuel equivalence ratio and fuel calorific value of the combustible mixture, combustion instability faults can easily be induced by fluctuations in the air-fuel equivalence ratio and fuel calorific value. Through the above arrangement, it can be ensured that the air-fuel equivalence ratio and fuel calorific value of the combustible mixture entering the combustion chamber remain essentially unchanged, thus improving combustion stability.

[0025] 3. The present invention provides a double-layer hollow cup structure inside the main air intake component; the double-layer hollow cup structure includes: an inner hollow cup formed by an inner first guide plate and an outer hollow cup formed by an outer second guide plate; both the first and second guide plates are horn-shaped; the first horn opening at the outer end of the first guide plate corresponds to the outer end of the main air intake component, and the space enclosed inside the first guide plate forms a central mixing zone; the central mixing zone is suitable for mixing fuel and air introduced from the outer end of the main air intake component; the second horn opening at the outer end of the second guide plate is disposed inward relative to the first horn opening; the space enclosed inside the second guide plate and outside the first guide plate forms an intermediate mixing zone; the intermediate mixing zone is suitable for mixing fuel introduced from the front periphery of the main air intake component. The first guide vane contains air and fuel that has been mixed in the central mixing zone. The space outside the second guide vane forms an outer mixing zone. The outer mixing zone is suitable for mixing fuel and air introduced from the rear periphery of the main air intake and fuel and air that have been mixed in the intermediate mixing zone through the gaps in the second guide vane. This application adopts the above technical solution, by setting a central mixing zone, an intermediate mixing zone and an outer mixing zone. The main air and main fuel enter the pre-mixing chamber from three different positions of the main air intake, dividing the main air and main fuel into three parts. After each part of air and fuel is mixed, other air and fuel are combined, and the mixture is carried out step by step. Finally, the overall mixture is mixed, which helps to improve the uniformity of air and fuel mixing and improve combustion stability.

[0026] 4. The present invention provides a main swirler in the front part of the rear premixing chamber; the present application adopts the above technical solution, the main swirler has blades with a certain rotation angle, under the guiding action of the blades, the main air and the main fuel are mixed to form a rotating airflow with a certain circumferential speed, and are further mixed in the rear premixing chamber, and finally injected into the combustion chamber from the rear end in the form of a rotating jet for combustion. The rotating jet will also form a recirculation zone in the combustion chamber, so that the high temperature gas after combustion is returned and stabilized at the head of the combustion chamber, playing the role of ignition and stabilizing the combustion flame surface.

[0027] 5. The present invention provides a shift cyclone separator located at the rear of the shift premixing chamber. Using the above-mentioned technical solution, the shift fuel and shift air are mixed and then injected into the combustion chamber as a rotating jet through the shift cyclone separator for combustion. Similarly, the shift cyclone separator has blades with a certain rotation angle. Under the guiding effect of the blades, the shift fuel and shift air mixed in the shift premixing chamber are injected into the combustion chamber from the rear end as a rotating jet for combustion. This rotating jet simultaneously forms a recirculation zone in the combustion chamber, causing the high-temperature combustion gas to flow back after combustion and stabilize at the head of the combustion chamber, thus playing a role in ignition and stabilizing the combustion flame surface.

[0028] 6. The present invention provides a purge air channel inside the premixed chamber and the fuel channel; the purge air channel is connected to the combustion chamber through a purge air hole at the rear end; the present application adopts the above technical solution to prevent backfire from occurring when the recirculation zone is close to the rear end face of the fully premixed burner, and avoids the failure of burning out the fully premixed burner.

[0029] 7. The present invention provides a hollow purge rod in the premixing chamber, with the rear end of the purge rod located near the rear of the premixing chamber; the present application adopts the above technical solution to remove residual fuel by the purge rod when the fully premixed burner stops working; to prevent air in the combustion chamber from entering the fully premixed burner and mixing with the residual fuel, thus preventing spontaneous combustion or deflagration accidents.

[0030] 8. The present invention provides a purge cooling channel near the rear end of the purge rod, and provides cooling air holes on the outer periphery of the purge air channel, the cooling air holes being connected to the purge cooling channel; the present application adopts the above technical solution to cool the rear end of the purge rod, which is close to the combustion chamber and has a high temperature, by means of cooling air, so as to protect the purge rod.

[0031] 9. The main intake component of the present invention is provided with a connecting flange at its front end, and the main fuel passage and the standby fuel passage are both located inside the burner connecting flange. The present application adopts the above technical solution, which facilitates external connection through the connecting flange, and makes full use of the internal space of the connecting flange to set up the main fuel passage and the standby fuel passage, so that the arrangement of the fully premixed burner is more compact, reducing the volume and weight.

[0032] 10. The shift fuel channel of the present invention extends into a portion of the space of the shift premixing chamber; the shift fuel channel communicates with the shift premixing chamber through a shift fuel hole provided near the outer periphery of the end; the shift air hole is located in front of the shift fuel hole; the present application adopts the above technical solution so that the shift fuel injected by the shift fuel hole and the shift air injected by the shift air hole are fully and evenly mixed. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a cross-sectional view of the fully premixed burner provided in an embodiment of the present invention;

[0035] Figure 2 This is a three-dimensional structural diagram of the fully premixed burner provided in an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Main air inlet; 2. Main fuel inlet; 3. First guide vane; 4. Second guide vane; 5. Main air intake; 6. Main cyclone separator; 7. Standby air inlet; 8. Pre-mixing chamber; 9. Nozzle outer cylinder; 10. Rear pre-mixing chamber; 11. Nozzle inner cylinder; 12. Standby cyclone separator; 13. Purge cooling passage; 14. Purge air inlet; 15. Cooling air inlet; 16. Purge rod; 17. Standby fuel inlet; 18. Standby pre-mixing chamber; 19. Purge air passage; 20. Standby fuel passage; 21. Main fuel passage; 22. Main fuel chamber; 23. Main fuel passage inner wall; 24. Connecting flange; 25. Pre-mixing chamber inner wall; 26. Central mixing zone; 27. Intermediate mixing zone; 28. Outer mixing zone. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] like Figures 1 to 2 One specific embodiment of the fully premixed burner shown includes: a main air intake 5 and a nozzle outer cylinder 9 connected together, and a nozzle inner cylinder 11 spaced inside the nozzle outer cylinder 9.

[0043] like Figure 2 As shown, a plurality of evenly arranged main air holes 1 are provided on the outer wall of the main air intake component 5, and a plurality of evenly arranged duty air holes 7 are provided on the outer wall of the nozzle outer cylinder 9. A connecting flange 24 is provided at the front end of the main air intake component 5.

[0044] like Figure 1As shown, the main intake component 5 has a main fuel chamber 22 on its outer layer, and a pre-mixing chamber 8 inside the main intake component 5; the main fuel chamber 22 is adapted to communicate with the main fuel passage 21; the main fuel chamber 22 is connected to the pre-mixing chamber 8 through multiple main fuel holes 2. The main air hole 1 is connected to the pre-mixing chamber 8; the main fuel passage 21 is a channel with an annular cross-section. A rear pre-mixing chamber 10 with an annular cross-section is provided inside the nozzle outer cylinder 9; the rear pre-mixing chamber 10 is connected to the front pre-mixing chamber 8. A standby pre-mixing chamber 18 with an annular cross-section is provided inside the nozzle inner cylinder 11; the standby pre-mixing chamber 18 is adapted to communicate with the standby fuel passage 20, which is an annular cross-section channel fitted inside the main fuel passage 21; the standby air hole 7 is connected to the standby pre-mixing chamber 18; both the rear pre-mixing chamber 10 and the standby pre-mixing chamber 18 are adapted to communicate with the combustion chamber. The main fuel passage 21 and the standby fuel passage 20 are both located within the connecting flange 24.

[0045] like Figure 1 and Figure 2As shown, a plurality of main air holes 1 are uniformly arranged on the outer end and periphery of the main air intake component 5, and each main fuel hole 2 is arranged close to the main air hole 1. A double-layer hollow cup structure is provided inside the main air intake component 5; the double-layer hollow cup structure includes: an inner hollow cup formed by an inner first guide plate 3 and an outer hollow cup formed by an outer second guide plate 4; both the first guide plate 3 and the second guide plate 4 are horn-shaped; the first horn opening at the outer end of the first guide plate 3 corresponds to the outer end of the main air intake component 5, and the space enclosed inside the first guide plate 3 forms a central mixing zone 26; the central mixing zone 26 is suitable for mixing fuel and air introduced from the outer end of the main air intake component 5; the second horn opening at the outer end of the second guide plate 4 is opposite to the first horn opening. The opening is positioned inwards; the space enclosed by the second guide plate 4 and the first guide plate 3 forms an intermediate mixing zone 27; the intermediate mixing zone 27 is suitable for mixing fuel and air introduced from the front outer periphery of the main intake 5 and fuel and air mixed in the central mixing zone 26 introduced through the gaps in the first guide plate 3; the space outside the second guide plate 4 forms an outer mixing zone 28; the outer mixing zone 28 is suitable for mixing fuel and air introduced from the rear outer periphery of the main intake 5 and fuel and air mixed in the intermediate mixing zone 27 introduced through the gaps in the second guide plate 4. A main cyclone separator 6 is provided in the front part of the rear premixing chamber 10. A shift cyclone separator 12 is provided in the rear part of the shift premixing chamber 18. Both the main cyclone separator 6 and the shift cyclone separator 12 have multiple blades with a certain rotation angle. The area of ​​the pre-premixing chamber 8 is formed by the inner wall 25 of the cylindrical pre-premixing chamber and the main cyclone separator 6, inside the main intake component 5. A purge air passage 19 is fitted inside the standby premixing chamber 18 and the standby fuel passage 20; the purge air passage 19 communicates with the combustion chamber through a purge air hole 14 at its rear end. A hollow cylindrical purge rod 16 is provided inside the standby premixing chamber 18, with its rear end positioned near the rear of the standby premixing chamber 18. An annular purge cooling passage 13 is provided near the rear end of the purge rod 16, and cooling air holes 15 are provided on the outer periphery of the purge air passage 19, communicating with the purge cooling passage 13. The standby air hole 7 passes through the main cyclone separator 6 and communicates with the standby premixing chamber 18. The outer wall of the purge rod 16, together with the inner wall 25 of the front premixing chamber and the inner wall 23 of the main fuel passage, forms an area of ​​an annular duty fuel passage 20. The duty fuel passage 20 extends into a portion of the space of the duty premixing chamber 18. The duty fuel passage 20 communicates with the duty premixing chamber 18 through a duty fuel hole 17 located near the outer periphery of the end. The duty air hole 7 is located in front of the duty fuel hole 17.

[0046] The working principle of the fully premixed burner described in this application is briefly described as follows: The main air participating in combustion enters the pre-premix chamber 8 through the main air hole 1 on the main air intake 5; the main fuel participating in combustion enters the main fuel chamber 22 designed in the main air intake 5 through the main fuel channel 21, and is injected into the pre-premix chamber 8 through the main fuel hole 2 opened on the main air intake 5; considering that when the main air enters the pre-premix chamber 8 through the main air hole 1, a local backflow entrainment area will be formed on the back side of the main air hole 1, the position of the main fuel hole 2 is opened near the main air hole 1, which is beneficial to enhance the mixing of air and fuel and improve the uniformity of fuel mixing. The horn-shaped inner first guide plate 3 and the horn-shaped outer second guide plate 4 divide the pre-mixing chamber 8 into three fuel-air mixing zones: a central mixing zone 26, an intermediate mixing zone 27, and an outer mixing zone 28. The main air and main fuel entering from the left end face of the main intake component 5 are mixed in the central mixing zone 26 of the pre-mixing chamber 8; the main air and a portion of the main fuel entering from the cylindrical wall of the main intake component 5 are mixed in the intermediate mixing zone 27 of the pre-mixing chamber 8; and the remaining main air and main fuel are mixed in the outer mixing zone 28 of the pre-mixing chamber 8. This zoned mixing design divides the main air and main fuel into three parts, each containing air... After being mixed with fuel, the air and fuel are further mixed together, which helps to improve the uniformity of air and fuel mixing. After the main air and main fuel are premixed in the pre-mixing chamber 8, they flow through the main cyclone separator 6. The main cyclone separator 6 has blades with a certain rotation angle. Under the guidance of the blades, the main air and main fuel mixed air form a rotating airflow with a certain circumferential velocity, and are further mixed in the rear premixing chamber 10. Finally, they are injected into the combustion chamber from the right end in a rotating jet manner for combustion. The rotating jet will also form a recirculation zone in the combustion chamber, so that the high-temperature gas after combustion flows back and is stabilized at the head of the combustion chamber, which plays a role in ignition and stabilizing the combustion flame surface. The air participating in the standby combustion enters the standby premixing chamber 18 through the standby air hole 7, and is mixed with the standby fuel that flows through the standby fuel channel 20 and the standby fuel hole 17 into the standby premixing chamber 18 in sequence. After mixing, it passes through the standby cyclone separator 12 and forms a rotating jet that is injected into the combustion chamber for combustion. After the purge air enters the purge air passage 19, part of it enters the purge cooling passage 13 through the cooling air hole 15 to cool the right end of the purge rod 16 before entering the combustion chamber. The other part is sprayed into the combustion chamber through the purge air hole 14 to prevent the recirculation zone from getting close to the right end face of the fully premixed burner and causing backfire, thus preventing damage to the fully premixed burner.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A fully premixed burner, characterized in that, include: The main intake component (5) has a main fuel chamber (22) on its inner outer layer and a pre-mixing chamber (8) inside the main intake component (5); the main fuel chamber (22) is adapted to communicate with the main fuel passage (21); the main fuel chamber (22) is connected to the pre-mixing chamber (8) through multiple main fuel holes (2); multiple main air holes (1) are provided on the outer wall of the main intake component (5), and the main air holes (1) are connected to the pre-mixing chamber (8); the main fuel passage (21) is a channel with an annular cross section; The nozzle outer cylinder (9) is connected to the main air intake component (5); a rear premixing chamber (10) with an annular cross section is provided inside the nozzle outer cylinder (9); the rear premixing chamber (10) is connected to the front premixing chamber (8); The nozzle inner cylinder (11) is spaced inside the nozzle outer cylinder (9); an annular cross-section premixing chamber (18) is provided inside the nozzle inner cylinder (11); the premixing chamber (18) is adapted to communicate with the premixing fuel passage (20), which is an annular cross-section passage fitted inside the main fuel passage (21); multiple premixing air holes (7) are provided on the outer wall of the nozzle outer cylinder (9), which communicate with the premixing chamber (18); both the rear premixing chamber (10) and the premixing chamber (18) are adapted to communicate with the combustion chamber; The main air intake (5) is provided with a double-layer hollow cup structure; the double-layer hollow cup structure includes: a hollow cup inner layer formed by an inner first guide plate (3) and a hollow cup outer layer formed by an outer second guide plate (4); Both the first guide vane (3) and the second guide vane (4) are trumpet-shaped; The first horn opening at the outer end of the first guide plate (3) corresponds to the outer end of the main air intake (5), and the space enclosed inside the first guide plate (3) forms a central mixing zone (26); the central mixing zone (26) is suitable for mixing fuel and air introduced from the outer end of the main air intake (5); The second horn opening at the outer end of the second guide plate (4) is positioned relatively inward relative to the first horn opening; the space enclosed by the interior of the second guide plate (4) and the exterior of the first guide plate (3) forms an intermediate mixing zone (27); the intermediate mixing zone (27) is suitable for mixing fuel and air introduced from the front outer periphery of the main air intake (5) and fuel and air mixed in the central mixing zone (26) introduced through the gap provided in the first guide plate (3); The space outside the second guide plate (4) forms an outer mixing zone (28); the outer mixing zone (28) is suitable for mixing fuel and air introduced from the rear outer periphery of the main air intake (5) and fuel and air mixed in the intermediate mixing zone (27) introduced through the gap provided in the second guide plate (4).

2. The fully premixed burner according to claim 1, characterized in that, Multiple main air holes (1) are uniformly arranged at the outer end and outer periphery of the main air intake component (5), and each main fuel hole (2) is arranged close to the main air hole (1).

3. The fully premixed burner according to claim 1 or 2, characterized in that, A main cyclone separator (6) is provided in the front part of the rear premixing chamber (10).

4. The fully premixed burner according to claim 1 or 2, characterized in that, A cyclone separator (12) is provided in the rear part of the premix chamber (18).

5. The fully premixed burner according to claim 1 or 2, characterized in that, A purge air passage (19) is provided inside the premix chamber (18) and the fuel passage (20); the purge air passage (19) is connected to the combustion chamber through a purge air hole (14) at the rear end.

6. The fully premixed burner according to claim 5, characterized in that, A hollow purge rod (16) is provided inside the duty premix chamber (18), with the rear end of the purge rod (16) located near the rear of the duty premix chamber (18).

7. The fully premixed burner according to claim 6, characterized in that, A purge cooling channel (13) is provided near the rear end of the purge bar (16), and a cooling air hole (15) is provided on the outer periphery of the purge air channel (19), and the cooling air hole (15) is connected to the purge cooling channel (13).

8. The fully premixed burner according to claim 1 or 2, characterized in that, The front end of the main air intake component (5) is connected to a connecting flange (24), and the main fuel passage (21) and the duty fuel passage (20) are both located inside the connecting flange (24).

9. The fully premixed burner according to claim 1 or 2, characterized in that, The duty fuel channel (20) extends into part of the space of the duty premix chamber (18); the duty fuel channel (20) is connected to the duty premix chamber (18) through the duty fuel hole (17) provided near the outer periphery of the end; the duty air hole (7) is located in front of the duty fuel hole (17).

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